The present invention relates to a semiconductor device, and particularly to a semiconductor switching device for a semiconductor converter device, which switching device has a built-in, current-sensing diode to measure the parasitic-diode current.
In a semiconductor converter device, it is generally known that when generating a shift in electric current, or a commutation among the device elements, by switching the constituent semiconductor switching device, is desirable to determine the optimal timing of the switching in order to reduce the switching loss. The timing of the switching is determined by detecting the current flowing in parasitic diodes integrally formed in the semiconductor substrate of the semiconductor switching device. In the case of a voltage-driven, MOS-type semiconductor device, the parasitic diodes consist of a region of the first conductivity type and a channel region of the second conductivity type formed in the surface portion of the region of the first conductivity type. In the case of a current-driven, bipolar-type semiconductor element, the parasitic diodes consist of a region of the first conductivity type and the base region of the second conductivity type formed in the surface portion of the region of the first conductivity type.
It is also well known that detecting a current flow in the parasitic diodes is quite difficult. Consequently, the conventional method of adjusting the switching timing has been to confirm the timing with a circuit external to the semiconductor elements. However, confirming the switching timing by actually assembling an external circuit requires much time and expense.
A first object of the present invention is to provide a semiconductor element that can easily detect a current flowing in the parasitic diodes existing internally to the semiconductor substrate of the switching device.
A second object of the present invention is to provide a semiconductor switching device for a semiconductor converter device which is capable of achieving switching operations with only half the losses of the conventional semiconductor converter devices.